Structural and functional analysis of a polyoma-related mammalian plasmid (L factor): the enhancer activity and plasmid establishment. - H. Yoshimura; Y. Ikeda; M. Yoshimoto; S. Tamaki; K. Hanada; T. Kusano; Takashi Kohda; H. Saito; M. Oishi (Nucleic Acids Res., 1991)